Bag closure



Jan. 15, 1952 A. E. SCHENCK BAG CLOSURE 3 Sheets-Sheet 1 Filed June 16,1947 INVENTOR. AETHl/E E. ScHEA/cK 1, ATTORNEYS A. E. SCHENCK Jan. 15,1952 BAG CLOSURE 3 Sheets-Sheet 2 Filed June 16. 1947 ZNVENTOR. ARTHUR EJCHENCK BY fie,

ATTORNEYS Jan. 15, 1952 A. E. SCHENCK BAG CLOSURE 3 Sheets-Sheet 3 FiledJune 16, 1947 INVENTOR. E. ScHE/vcK Y flail, w W

ARTHUR ATTORNEYS Patented Jan. 15, 1952 BAG CLOSURE Arthur E. Schenck,Woodhaven, N. Y., assignor to Bemis Bro. Bag Com a corporation of Misspany, Minneapolis, Minn., our! Application June is, 1947, Serial No.754,987

1 Claim. 1

, This invention relates to new and useful improvements in bag closuresand more particularly to closures for sealing the open tops of flexiblewalled bags of the intucked type, and wherein the bag top walls arepressed into flatwise relation before sealing the bag mouth.

. Numerous attempts have heretofore been made to develop a bag closurewhich would be simple and inexpensive in construction, and which whencompleted would positively seal the bag mouth against leakage andsifting. Bags have heretofore been made wherein one of the bag top wallswas projected above the remaining bag top walls to provide an integralflap extending the width of the bag mouth, whereby when the bag topwalls were pressed into flatwise relation, said flap could be foldedover the flattened bag top walls and secured to the face of the oppositewall, thereby to seal the bag mouth. In such closures it has beenextremely difllcult to render the corners of the sealed bag topsiftproof, because portions of the contents of the bag, particularly iffinely pulverized, would find its way between the plies of the flattenedbag top walls to the extreme corners of the bag top at each end thereofwhere it might sift through because of the inability to tightly sealsuch cornersby folding the extended flap into sealing engagement withthe opposite wall, as above described.

To overcome the difliculty now commonly experienced with such bagclosures, and particularly with bags of the intucked type, I have foundthat by providing what may be termed the back wall of the bag top withan upwardly projecting flap, and then forming the top of the bag wallsin such a manner that the top edges of the intucked edge walls aredisposed at an elevation above the edge of the front wall of the bagtop, that a leakand sift-proof closure may readily be obtained byfolding the extending flap of the rear wall and the projecting ends ofthe intucked walls over into fiatwise relation with the upper portion ofthe front wall, and then adhering the flap and portions/of the edgewalls to the front wall by a suitable adhesive, that the danger ofleakage or sifting of the contents of the bag therefrom at the cornersof the bag closures may be completely eliminated.

It is therefore an object of the present invention to provide a closurefor bag bodies of the intucked type, whereby the mouths of such bags maybe closed and sealed in a manner to positively prevent leakage orsifting of the contents from the bags through the closed tops thereof,even A further object is to provide a tubular bag body blank of theintucked type having one of relatively wider walls projected upwardlyabove the top edges of the remaining bag top walls to provide anintegral closure flap, and wherein the upper marginal edge portions ofthe intucked walls are disposed at an elevation between the upper andlower edges of the relatively wider walls of the bag body, whereby whenthe upwardly projecting closure flap is subsequently folded over intofiatwise engagement with the opposed or front wall on a line coincidentwith the top edge of said opposed wall, or along a fold line spaceddownwardly from the upper edge of the opposed wall, the projecting endsof the intucked walls are simultaneously folded into flatwise engagementwith the opposed or front wall and adhered thereto by a suitablethermo-plastic or other adhesive suitable for the purpose. thereby toeffect a closure which will be leakand sift-proof.

Other objects of the invention reside in the provision of a bag closurewhich is particularly well adapted to bags of the intucked type, wherebythe bag mouth walls may be expeditiously folded into closing and sealingrelation to provide a hermetically sealed closure which will withstandrough handling without danger of the contents thereof sifting from thecorners or ends of the closed bag top; in the manner of trans verselysevering the tube from which the tubular bag body blanks are formedwhereby an upwardly projecting integral closure flapis provided at thetop of the bag body without waste, and without in any way interferingwith the formation of the bag bottom; and in the formation of the uppermarginal edge portions of the bag top walls whereby a seal tight closuremay be effected with a minimum of operations.

Other objects of the invention will appear from the followingdescription and the accompanying drawings and will be pointed out in theannexed claim.

In the accompanying drawings there has been disclosed a structuredesigned to carry out the various objects of the invention, but it is tobe understood that the invention is not confined to the exact featuresshown, as various changes may be made within the scope of the claimwhich follows.

, In the drawings:

Figure 1 is a front view of a tubular bag body blank showing the novelarrangement of the bag top walls prior to being folded into closing andthough the bags .are roughly handled in transit. sealing relation;

' the bag top, the intucked edge walls being shown extending above'thetop edge of the front wall;

Figure 7 is a similar view showing the integral flap of the rear wallpartially folded over the upper marginal edge of the front wall; 7

Figure 8 is a view showing the completed 010- sure;

Figure 9 is a detail sectional view substantially on the line 9 ofFigure 6, on a larger scale;

Figure 10 is a detail sectional view on the line v Ill-l0 of Figure 8;

Figure 11 is a detail sectional view on the line "-4! of Figure 6;

Figure 12 is a detail sectional view on the line i2l2 of Figure 8;

Figure 12-A is a side elevation of a closed bag top, artially brokenaway to illustrate the intucked wall portions folded against the frontwall;

Figure 12-B is a detail sectional view similar to Figure 10, showing abag top closure wherein the bag top walls are folded transversely alongthe line b-b, shown in Figure 6; and

Figures 13, 14 and 15 are views showing the formation of a self openingsquare bag bottom of more or less conventional design.

In the selected embodiment of the invention herein disclosed, there isillustrated in Figures 1 and 2, a tubular bag body blank comprisingfront and rear walls 2 and 3, and opposed edge walls 4-4, shown intuckedbetween the front and rear walls.

An important feature of the present invention resides in the formationof a closure which, when sealed, will be substantially sift-proof inconstruction, whereby finely pulverized materials may be safely shippedin the bags or containers without danger of leakage or portions of thecontents of the bags sifting therefrom at the corners of the closed bagtops.

The novel closure herein disclosed requires that the transverse severingof the tube from which the tubular bag body blanks are out be such thatwhen the tubular bag body blanks are cut from the tube, the upper edge 5of the front wall 2 will be disposed at an elevation below the upperedge 6 of the rear wall 3, and the upper edges I of the intucked edgewalls 44 will be disposed between the upper edges 5 and 6 of the frontand rear walls, respectively, as clearly illustrated in Figures 1 and 6.In other words, if the blank from which the bag body is made is openedup or stretched out, as shown in Figure 3, the upper edge of the blankwill be upwardly stepped from its opposed edges, and the lower edge willbe similarly stepped or notched to provide the top edge of the nextfollowing body blank.

The dot and dash lines 8 and 9, shown in Figure 3, indicate fold lines,and lines ii and I2 indicate similar fold lines, whereby the blank isdivided into the front and rear panels 2 and 3, respectively, and edgewall panels 4-4. The narrow elongated panel l3 shown at the right sideof Figure 3 provides a pasting flange to which the marginal 4 edgeportion") of panel 2 is pasted in the formation of the tubular bag bodyblank, shown in Figures and 2.

By severing the tube as above described, when the tubular bag bodyblanks are formed in the usual manner, the upper marginal edge portionof the rear wall will form, in effect, a flap l4, which extends abovethe upper edges of the front and edge walls 2 and 4, respectively, ofthe bag top, as clearly illustrated in Figures 1, 6 and 7.

To close and seal a bag top in accordance with the present invention,the upper intucked edge wall portions and the flap i4 are folded overthe upper edge 5 of the front wall 2, and are suitably bonded to thefront wall by a suitable adhesive. indicated at 15 in Figures 6 and 7.In practice it has been found that a thermo-plastic or thermosettingadhesive adequately lends itself for use to secure the bag top walls inclosing relation, because they require heat and pressure to complete theseal whereby the adhesive will flow into all of the crevices andinterstices of the bag top walls to thereby render the sealed bag topssift-proof and leak-proof, when completed as shown in Figure 8.

The folding of the upper projecting portions of the edge walls 4 overthe top edge of the front wall simultaneously as the flap [4 is foldedinto sealing engagement therewith, is of extreme importance because byso folding the upper ends of the edge walls over the front wall, thereis no possible way that the contents of the bag body may sift betweenthe plies of said walls to the atmosphere.

To close a bag top such as herein disclosed, the flap I4 and the exposedupper edge portions 'll of the edge walls 4--4 may be folded along theline H into engagement with the adhesive coated surface ii of the frontwall 2 of the bag top, as will be understood by reference to Figures 1,6, '7 and 12A, after which heat and pressure is applied to theoverfolded bag top walls to thereby cause the thermo-plastic adhesive tobecome reactivated and thereby bond together the has top walls tohermetically seal the bag mouth.

In Figures 6 and '7 the flap l4 and projecting top ends I of theintucked edge walls are shown folded along the top edge of the frontwall 2 (line H), but, if desired, the bag top walls may be transverselyfolded along a fold line b-b, spaced downwardly from the upper edge ofthe front wall 2, as clearly illustrated in Figures 6 and 12-B.

It will be noted by referring to th blank shown in Figure 3, that thetransverse severing of the tube to form the tubular bag body blanks issuch that the uppermost edge ii of the blank, which constitutes the edge8 of the closure flap I4 shown in Figure 1, extends beyond the foldlines 9 and II, or in other words, into the edge walls 4-4. By soextending the edge It, when the edge walls are intucked between thefront and rear walls of the bag body, as shown in Figures 1 and 2, theportions I! are folded around simultaneously with the intucking of theedgewalls. as perhaps best shown in Figures 6 and '7, and 12-A, and aresubsequently folded into bonding engagement with the adhesive coatedsurfac l5 of the front wall 9, as shown in Figures 7 and 8.

In like manner, the edge portions ll of the upper edge of the blankshown in Figure 3 extend beyond the score lines 8 and i2, whereby asimilar result is obtained at the ends of the top edge 5 of the frontwall 2, as shown at IS in Figures 6 and 7.

In Figures l3, l4 and 15 there is illustrated a conventional form ofbottom, generally known to the trade as an S. O. S., or self-openingsquare bottom. It will be noted that the. particular manner in which thetube from which the tubular bag body blanks are formed is severed toform the bag blank does not in any way interfere with the subsequentformation of the bag bottom, whether it be an S. O. S., satchel type, orpinch bottom. In other words bag bottoms of above types may be formed inthe usual manner and by conventional bottoming machinery or equipment.When making S. O. S. on satchel bottoms, the lower portions of the frontand rear walls 2! and 22 are expanded or outwardly folded, as shown inFigure 13, whereby the lower portions 23 of the edge walls are inwardlyfolded. A suitable adhesive 24 may then be applied to the walls asindicated at 24 in Figure 13, and preferably in sub stantially thepattern illustrated, after which the wall portion 22 is folded inwardlyover the edge wall portions 23 along a fold line 25. The wall portion 2|is then folded inwardly over the previously folded wall portions alonga. fold line 26, to the position shown in Figure 15, thereby com pletingthe formation of the bag bottom.

The bottom of the bag constitutes no part of the present invention andit is therefore deemed unnecessary to further describe the same.

In some instances it may be deemed desirable to fold the top wallstransversely on a line spaced downwardly from the upper edg of the frontwall 2, as indicated by the line b-b in Figure 6. When the bag top wallsare thus folded, an added wall thickness is obtained across the centerof the bag top because of the transverse folding of the upper marginaledge portion 5 of the front wall 2, as will be understood by referenceto Figure 6. This, however, is not objectionable, and adds somewhat tothe strength of the bag closure. By cutting the tubular blank ends asherein disclosed, the flap ll may be formed without waste, as will beunderstood by reference to the drawings.

In the drawings I have shown the invention applied to bags in which thwalls are of single ply. Obviously, the invention may be applied tomultiwall bags with equal results, as will readily be understood.

It will be apparent to those skilled in the art that I have accomplishedat least th principal objects of my invention, and it will also beapparent to those skilled in the art that the embodiments hereindescribed may be variously changed and modified Without departing fromthe spirit of the invention, and that the invention is capable of usesand has advantages not herein specifically described; hence it will beappreciated that the herein disclosed embodiments are illustrative only,and that my invention is not limited thereto.

I claim as my invention:

A collapsed gusset bag wherein the top of the bag is composed of front,rear and edge walls and wherein the edge walls are intucked between thefront and rear walls, the upper marginal edge portion of the rear wallprojecting above the top edge of the front wall to provide an integralclosure flap, and the upper ends of the intucked edge walls beingdisposed at an elevation between the upper edges of the front and rearwalls and having substantially triangular portions integral with theedges of the rear wall extending up wardly and outwardly to the ends ofthe top edge of the rear wall flap and similar portions integral withthe edges of the front wall extending downwardly and inwardly to the topedge of the front wall each to a point spaced inwardly from the adjacentside edge of the front wall, said top portion of said collapsed baghaving a trans verse fold line adjacent to but spaced downwardly fromthe top edge of said front wall, said front wall having a transversestrip of adhesive extending entirely across said front wall downwardlyfrom said folded line, said adhesive securing said closure flap whensaid top position of said collapsed bag is folded on said transversefold line.

ARTHUR E. SCHENCK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,015,007 Cutler Jan. 16, 19121,920,322 Rosmait Aug. 1, 1933 2,000,345 Miller May '7, 1935 2,274,934Piazze Mar. 3, 1942 2,294,848 Moore Sept. 1, 1942 2,345,434 SterlingMar. 28, 1944 2,370,680 Moore Mar. 6, 1945

